The Carton Council of North America, American Chemistry Council, Association of Postconsumer Plastic Recyclers, Foodservice Packaging Institute and the National Association for PET Container Resources co-funded a MRF Material Flow Study to find ways to optimize the recycling of their packaging after it goes into the trash.
Changes to the sorting processes could improve recovery
They looked at where packages end up in a sorting facility, why packages flow in certain ways and what potential changes to the sorting processes could improve recovery.
The report states: “This study examined the behavior of numerous individual products in the MRF, yielding data on cups, clamshells, containers, domes/trays, bottles, tubs, lids, gable-top and aseptic cartons, and other materials.”
The three goals were: to learn how materials similar to the test samples and other study materials would flow through typical MRF environments; determine which of the study materials, not currently accepted by MRFs, could potentially be recycled using existing
MRF infrastructure; and start to develop an understanding of what sort processes could be modified to allow effective recovery of sample materials.
It found the form of a package had a strong influence on the loss of packaging to the paper streams. Plastic clamshells had a higher likelihood of flattening and moving with the paper streams.
Bottles, cups and container had lower loss rates
The rounder materials (including bottles, cups and containers) had lower loss rates, and less than 5% was lost at the top performing MRFs. Small, lightweight water bottles were more likely than other bottles to move with the paper with a loss rate of 15%.
Cups, containers and clamshells still enter the MRFs in much lower quantities than bottles. They made up 11% of the plastics stream, even with the seeded materials.
The MRFs chosen to represent a wide diversity of facilities process recyclables nationwide included;
• 1 dual stream and 4 single stream facilities
• Throughput range (tons per hour): 10 tph – 35 tph
• Four different equipment manufacturers
• Number of optical sorters ranged from 0–5
• Varying combinations of disc screens and other mechanical separation equipment.
Jim Frey, CEO, Resource Recycling Systems (RRS) said everyone plays a role in ensuring recycling is effective and efficient, and there are actions that can be taken at all steps in the process to ensure items get their maximum value when they are recycled.
“One such action is asking residents, and other recycling customers, not to flatten items before placing them in recycling containers,” he said.
Best practices for accurate 2d/3d separation in single stream MRFs:
• Avoid loading screens past their
design throughput
• Clean screens of material that are
wrapped around the shafts
• Replace worn and damaged discs
• Minimize compaction of material by
residents and collection trucks
• Keep material dry
“The study found three-dimensional objects (packages in their original form) versus two-dimensional (flattened/crushed objects) have a higher likelihood of making it through the system to the appropriate container lines and bales. This is not only a helpful finding but an actionable one which shows even everyday actions in the home can boost recovery.”
The organizations are now looking to finding ways to apply this knowledge to increase recovery and work closely with stakeholders, such as communities and facilities. The study was developed and delivered by RRS, Reclay StewardEdge and Moore Recycling Associates.
The five national trade associations:
THE AMERICAN CHEMISTRY COUNCIL
The Plastics Division of the American Chemistry Council (ACC) represents resin manufacturers and advocates for unlimited opportunities for plastics and promotes their economic, environmental and societal benefits.
THE ASSOCIATION OF POSTCONSUMER PLASTIC RECYLERS
APR represents companies who acquire, reprocess and sell the byproduct of more than 90% of the postconsumer plastic processing capacity in the US, Canada and Mexico.
THE CARTON COUNCIL
The Carton Council is composed of four carton manufacturers, Elopak, SIG Combibloc, Evergreen Packaging and Tetra Pak, and associate member, Weyerhaeuser.
THE FOODSERVICE PACKAGING INSTITUTE
Established in 1933, the FPI is the trade association for the foodservice packaging industry in North America. FPI's members include raw material and machinery suppliers, packaging converters, foodservice distributors and operators/retailers.
THE NATIONAL ASSOCIATION FOR PET CONTAINER RESOURCES
Founded in 1987, NAPCOR is the trade association for the PET plastic packaging industry in the US and Canada. NAPCOR is dedicated to promoting the PET package; to overcoming hurdles to the successful recycling of PET; and to communicating the attributes of the PET container as a sustainable package.